Voltage regulators generally convert an input, or supply voltage, to a controlled output voltage where the control is based on a reference voltage. While a constant output voltage is usually desired, in practice the output voltage of a conventional linear voltage regulator exhibits some fluctuation in response to variations on the supply line input voltage. Line rejection is the measure of the output fluctuation with respect to the variation in the input voltage. Current design trends for circuits that rely on regulated voltage are becoming increasingly intolerant of fluctuation and are requiring increased line rejection. Attempts to improve line rejection in conventional voltage regulators often require cascading two or more regulators, which results in increased component count, reduced efficiency and/or increased circuit complexity, all of which may be inappropriate for some applications.
Although the following Detailed Description will proceed with reference being made to illustrative embodiments, many alternatives, modifications, and variations thereof will be apparent to those skilled in the art.